Question Library

(a) State an indicator suitable for the titration of; (i) dilute HCl and NaOH\(_{3(aq)}\) (ii) dilute CH\(_3\)COOH and KOH\(_{(aq)}\) (iii) dilute HCl and NH\(_{3(aq)}\). Give a reason for your answer in each case. (b) Calculate the volume of water that would be added to 50 cm\(^3\) of 0.10 mol dm\(^{-3}\) of HCI to dilute it to 0.010 mol dm \(^{-3}\) (c) Name one gas that could be used to demonstrate the fountain experiment.

Credit will be given for strict adherence to the instructions, for observations precisely recorded, and for accurate inferences. All tests, Observations, and inferences must be clearly entered in your answer book, in ink, at the time they are made. C is a mixture of two inorganic salts. Carry out the following exercises on C. Record your observations and identify any gas(es) evolved. State the conclusion you draw from the result of each test. (a) Put all of C in a test tube and add about 10 cm\(^3\) of distilled water. Stir, filter, and keep the filtrate and the residue. (b) Put the residue into a test tube and add about 5 cm\(^3\) of dilute HCl. Shake to dissolve (i) To about 2 cm\(^3\) of the solution, add NaOH\(_{(aq)}\) in drops and then in excess (ii) To another 2 cm\(^3\) portion of the solution, add NH\(_{3(aq)}\) in drops and then in excess. (c) To about 2 cm\(^3\) portion of the filtrate, add few drops of dilute HNO\(_3\), and then AgNO\(_{3(aq)}\) a followed by aqueous NH\(_3\) in excess.

All your burette readings (initial and final) as well as the size size of your pipette, must be recorded but no account of experimental procedure is required. All calculations must be done in your answer book. A is a solution containing 1.04 g HCl per 500 cm\(^3\) of solution. B was prepared by diluting 50.0 cm\(^3\) of a saturated solution of Na\(2\)CO\(_3\) at room temperature to 1000 cm\(^3\) (a) Put A into the burette and titrate it against 20.0 cm\(^3\) or 25.0 cm\(^{3}\) portions of B using methyl orange as indicator. Repeat the titration to obtain consistent titres. Tabulate your results and calculate the average volume of acid used. 9b) From your results and information provided above, calculate the; (i) concentration of A in moldm\(^{-3}\) (ii) concentration of B in mol dm\(^{-3}\) (iii) solubility of Na\(_2\)CO\(_3\) in mol dm\(^{-3}\) (iv) volume of CO\(_2\) that would be liberated from 1 dm\(^3\) of B if the titration were carried out at s.t.p. The equation for the reaction is Na\(_2\)CO\(_{3(aq)}\) + 2HCl\(_{(aq)}\) \(\to\) 2NaCl\(_{(aq)}\) + H\(_2\)O\(_{(l)}\) + CO\(_{2(g)}\) [H = 1; C = 12; O = 16; Na = 23; Cl = 35.5; Molar volume of gas at s.t.p = 22.4 dm\(^3\)]

Which of the compounds above is a tertiary alkanol?

Use the diagram above to answer the question below: The fuel gas labelled L is

Use the diagram above to answer the question below: The alternative raw material labelled M is

In question number 25 above choose the best option from letters A - D that best complete the gap

Read the following passage carefully and answer the questions on it. Have you always thought that insects are nothing more than a nuisance? Would you like the world to be free of these annoying pests ? Do you spray them swat them. or step on them at every opportunity? Before declaring war on every bug that crosses your path, why not try to learn something about their world? After all, with a population that outnumbers humans by about 200 million to one you can be sure that insects are here to stay! A brief look at just a few of these amazing creatures might well convince you that insects deserve your respect. Consider flying insects for example: Mosquitoes can fly upside down. Some can even fly through the rain without getting wet - yes, actually dodging the raindrops! Some tropical wasps and bees buzz around at speeds of up to 72 kilometres per hour. One monarch butterfly of North America logged 3,010 kilometres on its migration flight. Hover flies can beat their wings more than a thousand times per second - much faster than humming-birds and dragon flies can fly backwards. Clearly then. insects are such accomplished fliers, unmatched by any other winged creature. The eyes of many insects serve as a compass. Bees and wasps, for instance, can detect the plane of polarised light. This enables them to locate the sun's position in the sky - even when it is hidden by clouds. Thanks to this ability, these insects can forage far from their nests and still navigate their way home unerringly. In the insect world, sounds and aromas are often used to find a mate - no small achievement when prospective mates are few and far between. Female emperor moths find a suitor by emitting a scent that is so potent that a male can i home n on its source from nearly 11 kilometres away. Crickets, grasshoppers, and cicadas prefer to make themselves heard. Even we humans can hear the amorous cicada as it converts its whole body into a sounding board. A large group of courting cicadas can create a noise louder than that of a drilling machine! Insects play a vital role in our daily life, about 30 percent of the foods we eat results from pollination by them. But pollination is only one of their useful functions. Insects keep the earth clean by means of an efficient recycling system, as they reprocess dead plant and animals. Scientists have observed that without insects the earth will be inundated with dead plant and animal matter. Insects also enrich the soil by liberating nutrients that make things grow. They are sorely missed when their work is not done. Consider what happened in Australia, which has become home to millions of cattle. Herds scattered dung everywhere. Besides being unsightly, the dung provided a breeding site for the bush fiy - a plague to both humans and cattle. So dung beetles were imported from Europe and Africa, and the problem was solved! Admittedly, some insects eat crops and carry disease. But only about one percent of the world's insects is considered as pests, and many of these cause damage because of the way man himself altered the environment. Even with their drawbacks, insects are an integral part of the natural world on which we depend. Scientists have pointed out that while insects can survive without us, we cannot survive without them. (a) In three sentences, one for each, summarise the characteristics of insects discussed in the passage. (b) In three sentences, one for each, summarise the important functions of insects discussed in the passage.

You had a quarrel with your best friend and have not been on speaking terms ever since. Now that you are about to leave secondary school, write to your friend giving at least three reasons why you should become friends again.

Write an article for publication in your school magazine on the problems of indiscipline in schools.

Write a letter to the Chairman of your school's Board of Governors on the need for a library in your school, requesting him to build and equip one for the school.

You are the chief speaker in a debate on the topic: It is the home and not the school that contributes more to moral laxity among students. Write your argument for or against the topic.

Write a story to illustrate the saying: Strike while the iron is hot.

Read the following passage carefully and answer the questions on it. Mr Cissey pulled on his trousers very hurriedly and dragged himself to the veranda. He was bent on getting to his office beforehis workers. The previous day, he had reprimanded his staff for regularly coming to work late, and threatened to give the sack to any of them who would repeat the offence. Today, he must get to work in time not only to serve as a role model but also to show that he really meant what he had said. He managed to squeeze himself behind the wheel of his car which was at least two sizes too small to accommodate his paunch. He inserted the ignition key and turned it but the car would not start; the engine just grumbled. On the second attempt, it coughed and finally roared to life on the third. It moved grudgingly to the gate and stopped. Cissey immediately realised that he would be caught in a traffic jam. It was evident that he would arrive at his workplace late. For about two hours, Cissey just sat, glued to his seat, fuming. Hard as he tried to control his temper, the misbehaviour of other drivers once prompted him to bawl at them. Then suddenly, after the interminable wait, the street cleared and Cissey sped off. It was almost three hours after leaving home that he got to his workplace. The staff were already there and when he entered the building, he found his secretary and the clerical staff apparently immersed in their assignments, with an air of dutifulness. One look at their boss warned them that they had better keep quiet to save their skin. But as soon as he closed the door to his office he heard soft voices mumbling words he could not understand. Worst of all, he heard subdued laughter from his secretary. Cissey immediately shot out of the chair ready to vent his spleen on these underlings but suddenly plopped bac into his seat. On second thoughts, he changed his mind. How could he castigate them for what they had not caused? (a) Why was Mr Cissey in a hurry to get to his office? (b) What two indications are there in the passage that Mr Cissey was a huge man? (c) How did Mr Cissey express his anger while caught in the traffic? (d) Why did Mr Cissey become angry with his staff? (e) What was the attitude of the staff towards their boss? (f) .,,when he entered the building ... What grammatical name is given to this expression as it is used in the passage? (ii) What is its function? (g) How could he castigate them for what they had not caused? What literary device is used in the expression above? (h) What is meant by the expression vent his spleen in the last paragraph? (i) For each of the following words, find another word or phrase which means the same and which can replace it as it is used in the passage: (i) reprimanded (ii) evident (iii) prompted (iv) interminable (v) immersed (vi) subdued.

Read the following passage carefully and answer the questions on it. Whenever I ask myself the question why I have not left this country for good, many answers rush to my mind, each striving to be.recognized as being the most convincing. I am reminded of the popular slogan that this country belongs to us, for which reason every one of us must join hands in trying to salvage it. I try to dismiss the argument by reasoning that it is foolhardy attempting to lend a helping hand where one's services are apparently not required. Then I am reminded that if I leave the country in a hurry just because of our political instability and economic hardship, my commitments to my nuclear family and extended family at home will suffer. I reply by saying that as soon as I get settled abroad. I would arrange for my famiiy to Join me. Other financial problems at home would be taken care of by my regular remittances. Would I then never think of going back home in future? Not until the situation in the country improved considerably, I would answer. And who do I expect to carry on with the task of national rehabilitation when the likes of me are all out of the country? Those who messed up the country in the first place, I would argue. And so on. This self-examination has been going on for the last ten years or so: meanwhile. I am yet to leave the country. When I wonder how many people think' as I do. I realize that we must" be very few. Indeed, not many have the slightest opportunity of absconding from the country; they do not have the place to run to, nor do they have the means of escape. Even among the elite who consider this possibility. the uncertainty of a future outside their fatherland intimidates them. And so we all end up staying and grumbling. (a) Why would the writer like to leave his country? (b) Why does the writer believe that he should not join in salvaging his country?' (c) What would make the writer return to his country? (d) Who does the writer suggest should carry on the task of national rehabilitation? (e) Give two reasons why it has not been easy for him and others to leave the country. (f) ...many answers rush to my mind. What figure of speech is used in this expression. (g). . the uncertainty of a future outside their fatherland (i) What grammatical name is given. to this expression as it is used in the passage? (ii) What is its function? (h) For each of the following words or phrase find another word or phrase which means the same and which can replace it as it is used in the passage. (i) for good. (ii) slogan, (iii) foolhardy; (iv) commitments; (v) absconding.